David at The Debate Link sticks a cautious toe into the abortion debate, asks when personhood begins. (Actually, he asked the question a few different ways, but one of them was when personhood begins.)
Here’s what “personhood” means to me: the ability to subjectively experience consciousness; to have thoughts and feel emotions; to have a personality. This ability, in humans, is located in the cortex of the brain, where all our thoughts and emotions take place.
Why am I so focused on the brain as the center of what we are? Because the brain is the only part of a person’s body that cannot be destroyed while leaving the person still alive.
To see what I mean, imagine that you get an emergency call: Someone close to you has been in a terrible accident. You rush to the hospital, and are told that your friend’s heart has been destroyed. However, a tourist from Belgium happened to die the same day, in the same hospital, and luckily is a tissue match for your friend. (Luckily for your friend, not so luckily for the dead Belgian).
Repeat the same thought exercise, except this time imagine different body parts being replaced with a part from the unfortunate Belgian. A hand transplant. A kidney. Ears. Hair. Lungs. No matter which part is replaced, it’s still your friend. You’re not mistaken to feel you have an ongoing relationship with this person, despite the new heart/hand/kidney/ear/hair/whatever.
Now imagine that the doctors say your friend’s brain was utterly destroyed in the accident. But not to worry – they have put in the Belgian’s brain. The doctors tell you that your friend now remembers an entirely different life, speaks a different native language, and has a completely new personality; but other than that, she’s still the same person you know.
Does that make any sense? Is this the same person you considered your friend? Most people would say no. The survivor of that operation wasn’t your friend; it was the Belgian tourist.
In science fiction movies like The Man With Two Brains, some people can be reduced to brains in jar, but they’re still themselves, and audiences have no trouble accepting that notion. Why does that ring true with us? Because it gets at a core truth. Our brains – and in particular, the personality imprinted in the cortex – is the one part of a person that cannot be destroyed and still leave the person in any sense intact. But as long as that part is retained, we are still, in a meaningful sense, the same person.
So when does personhood begin? I don’t know. But I know that it can’t possibly happen before the fetus has a fully functioning cerebral cortex, capable of supporting thought.
In particular, it’s not possible for there to be any thought or awareness before the emergence of pyramidal cell dendritic spines on neurons,1 which happens relatively abruptly at about the 28th week. Pre-dendritic spines, the cerebral cortex might as well be a pile of gray slush, in terms of how well it can actually function.
Once the dendritic spines are in place, does the fetus become a person that instant? I doubt it. I think a working cerebral cortex is a necessary condition of personhood (in human beings, anyhow – maybe Vulcans are different), but I don’t think it’s sufficient. Once a fetus has a fully working cerebral cortex, to some extent that’s like having a blank hard drive; the hardware is all in place, but the data is still to come.
Nonetheless, as far as abortion is concerned, I find the scientific facts reassuring. Personhood, as I understand it, can’t even begin to exist until at least the 28th week – and probably doesn’t exist in any meaningful form until well after that point. But virtually all abortions – even those abortions usually referred to as “late term” abortions – take place well before the 28th week of pregnancy.
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Is a newborn baby a person? I think so, although its personhood is perhaps in a developmental stage.
Both the elderly and the disabled are people, as I’ve defined personhood above. The exception is when someone’s cortex is so extremely disabled that it basically stops existing at all, as in the case of Terri Schiavo. I am, however, prepared to defend the proposition that someone in the same shape Terri Schiavo was in two years ago, is for all moral purposes dead, despite the fact that their body lives on.
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So if a fetus might be a person beginning sometime after the 28th week, do I think that post-28th week abortions should be banned?
First of all, I’m not certain that there are any post-28th week abortions of viable fetuses performed in the US. (As it’s usually used, the term “late term abortion” refers to abortions that take place at week 18 and thereafter.)
But insofar as any do take place, it’s likely most take place in order to protect the life or health of the mother. I’m not prepared to legally force mothers to sacrifice their bodies to save a fetus’ life, any more than I’m prepared to advocate for laws forcing fathers to donate their kidneys against their will should their children ever require them.
Besides, it ultimately comes down to trusting women. I think pregnant women are the people who are best able to judge when a very-late-term abortion is necessary (in consultation with their doctors). I’m not convinced that the Senate is in a good position to make that judgment call.
- The original supporting link has died, alas. For more references, see Dr. Michael Flower’s article on fetal brain development. From the conclusion: “Thus, if we return to those neocortical capacities most likely to engage our moral attention as we prepare to ascribe a protected status of fetal personhood (i.e. possible awareness and/or a discrete and sustainable bodily existence regularly achieved through birth), we might be led to conclude that it is probably not until after 28 weeks of gestation that the fetal human attains a level of neocortex-mediated complexity sufficient to enable those sentient capacities the presence of which might lead us to predicate personhood of a sort we attribute to full-term newborns.” For easier reading, see this article from the LA Times: “Starting about 28 weeks, there is a burst of connections made between the neurons in all parts of the neocortex by cells appropriately called interneurons. “The bulk of what we do with our brains,” Marin-Padilla said, “is done by these interneurons. These little guys allow you to write, play tennis and carry out a variety of complex functions.” Studies seem to support the notion that 28 weeks marks a dramatic turning point in the fetus’s brain development and is more important than birth itself.” [↩]